1. Field of the Invention
The present invention relates to a local routing establishment technique in a mobile communication network. More particularly, the present invention relates to a system and method for establishing a local routing which may allow different mobile stations connected together with the same Access Service Network GateWay (ASN GW) to transmit and receive traffic without delivering such traffic to a Home Agent (HA) by using their location information.
2. Description of the Related Art
A mobile WiMax network refers to a wireless network that supports services based on the Institute of Electrical and Electronics Engineers IEEE 802.16e-2005 standard. The IEEE 802.16e-2005 standard, which is the basis of mobile WiMax, adds mobility supportable technologies, such as handover and paging, to the original IEEE 802.16-2004 standard which is frequently referred to as a fixed WiMax.
Typically, the mobile WiMax network includes a Mobile Station (MS) or Subscriber Station (SS), an Access Service Network (ASN), and a Connectivity Service Network (CSN). The ASN includes a Base Station (BS) and an ASN GateWay (ASN GW). The CSN includes a Pre-Paid Service (PPS) server and an Authentication, Authorization and Accounting (AAA) server.
The mobile WiMax network may often use a Proxy Mobile Internet Protocol (PMIP) to provide Layer-3 (L3) mobility between the ASN GWs. For the above, the ASN GW acts as an agent of the PMIP, and there exists an MIP Home Agent (HA) in the CSN.
In a conventional mobile WiMax network, even though the same ASN GW connects different mobile stations, their traffic must always pass through the HA. If traffic between MSs is interactive in real time, such delivery of traffic to and from the HA may cause an unnecessary delay. Furthermore, in case of MSs available for a roaming service, such traffic delay may become more serious due to a greater physical distance between the ASN GW and the HA.
Therefore, there is a need to allow traffic to be transmitted and received without passing through the HA when different MSs are connected together with the same ASN GW.